Quick latch jig



J1me 10, 1947. V A. J. mm

QUICK LATCH J IG- Fild larch s, 1944 s Sheets-Sheet 1- w m A W V a 4 2 June 10, 1947. A. J. MATTER I 4 QUICK LATCH J'IG Filed larch s, 1944 s Sheets-Sheet 5 Patented June 10, 1947 UNITED STATES PATENT OFFICE I QUICK LATCH JIG Albert J. Matter, Park Ridge, Ill.

Application March 8, 1944, Serial No. 525,496

11 Claims.

This invention relates to a quick latch jig and more particularly to drill jigs and one of the obieets of this invention is the provision of novel latch means between the base and swingin cover of a jig. by means of which the cover may be v quickly and easily latched to the base and unlatched therefrom,

Another object is the provision of a jig latch which also serves as a handle or hand grip for raising and lowering the cover. Another object is to provide a latch whereby the cover may be unlatched from the base and raised into open position by one continuous upward swing of the latch and whereby the cover may be lowered upon the work and latched to the base by one continuous downward swing of the latch. Another object is to provide a latch which occupies two operative positions; namely, one position in which it latchingly engages with a latch member on the base and the other position in which it abuts against the cover, when raising and lowering the same. Another object is to provide tension means to hold the latch in either of said operative positions. 'Another object is to provide work clamping means having a preloaded tension.

With these and other objects and advantages in view this invention consists in the several novel features hereinafter fully described and claimed.

The invention is clearly illustrated in the drawings accompanying this specification, in which:

Fig. 1 is a plan of a drill jig embodying one form of the present invention and showing the cover in closed position.

Fig. 2 is a side elevation of the jig seen in Fig. 1.

Fig. 3 is an end elevation of the jig.

Fig. 4 is a detail view of the latch means partly in side elevation and partly in vertical longitudinal section taken on the line 44 of Fig. 1.

Fig. 5 is a plan of a slightly modified form of the invention.

Fig. 6 is a side elevation of the jig illustrated in Fig, 5 with a part of the cover shown in section taken on the line 6-45 of Fig. 5.

Fig. 7 is an end elevation of the jig seen in Figs. 5 and 6, and

Fig. 8 is a detail view of the modified latching means partly in side elevation and partly in ver tical longitudinal section taken on the line 8-8 of Fig. 5.

Referring to said drawings and first to Figs. 1 to 4 inclusive, the reference character l0 designates a base for supporting the piece of work and H designates a bushing carrying cover, pivotally mounted on the base. The base may be of rectangular form, and may be formed with a platelike body portion 12. having flanges I2a which project down from the marginal edges thereof to give the base added strength and rigidity. At the corners of the body portion the flangesare extended down slightly below the intermediate portions of the flanges to form short feet l3.

Extending up from the base at its rear end are cover carrying uprights N that are formed with hinge ears l5 at their upper ends which cooperate with hinge ears l6 formed on the rear edge of the cover. A pintle or pin ll extends through apertures in the hinge ears and pivotally connects the cover with the base. Rests or seats [8 are provided on the uprights l4 adjacent the hinge ears and cooperate with the edge IQ of the cover to hold the latter in its raised position,

Projecting horizontally from the front of the base opposite the hinge end is a bifurcated leg 20 formed at its free end with a short foot 2! that terminates in the same horizontal plane as the feet l3, and connecting the foot with the base are spaced vertical webs 22 which support between them a latch member 23 here shown in the form of a roller mounted on a pin 24 carried by the webs 22, which at this place are extended upward to provide two lugs 25, which cooperate with two downwardly projecting lugs 26 that are formed onthe cover, and support the free end of the cover on the lugs 25.

The lugs 26 are spaced apart to receive between them a latch 21 which is pivotally mounted on the lugs as by a pin 28carried by said lugs. As shown the pins 24, 28 are disposed one above the other when the cover is in down position. The latch is formed with a hook member 29 having a face 39 which extends along an arc of a circle that is non-concentric with respect to the axis of thepin '28, and said non-concentric face of the hook member is adapted to engage the latch roller 23 with a camming action whenever the latch is swung down into latching'engagement therewith, thus drawing the cover down and clamping the work in place. The non-concentric face of the hook member merges into an arcuate face 3| which abuts against the latch roller whenever the latch is swung down into its full latching engagementWith' the roller andacts as a stop member limiting the 'downward'swing of the latch. The front edge of the base is recessed as at I21) to receive the'hook member 29 when latchingly engaged with the latch roller.

Adjacent the-pivot of the latch the latter is formed with a shoulder 32 which, whenever the latch is swung upward to thelimit of its upward swing with respect to the covenabouts against a shoulder 33 formed on the front edge of the cover, whereby the latch and cover may swing as a unit (see Fig. 4). vided with a hand grip 34 desirably extending at right angles to the plane of the latch which hand grip is adapted to be gripped by the workman in manipulating the latch and cover.

Associated with the hand grip 34 are two lugs 35, 35 which project laterally from the latch. Thelug 35 is located approximately at the middle of the latch and the lug 36 is located at the upper edge of the latch and opposite the hand grip. The lug 35 provides a finger piece upon which the workman places his index finger and the lug 36 provides a thumb piece under which the workman places his thumb when. gripping.

the hand grip to unlatch the latch. The purpose of the finger and thumb pieces is to enable the workman to swing the latch upward when disen-.

gaging it from the latch roller without tilting the jig. In use there is considerable pressure exerted by the latch hook on the roller, but by taking hold of the hand grip as above described the workman can press down on the finger piece and press upward on the thumb piece while swinging the latch upward thereby disengaging the hook member from the latch roller without any danger of tilting the entire jig upward. When the workman wishes to unlatch and raise the cover, he swings the latch upward from the position seen in Fig. 2, untilthe shoulders 32, 33 abut (see Fig. 4) and by one continuous movement swings the cover into its raised position, the latch and cover moving'as a single unit. 7

To lower the cover the workman grasps the hand grip of the latch and swings-the latch and .cover down as a unit bringing the cover down upon the work and by continuing the downward swing of the latch theworkman latches the cover to the base.

Tension means are provided for holding the latch in each of its operative positions, that is to say, in its down position in complete latching engagement with the latch roller (see Fig. 2) and in its other position with its shoulder 32 abutting against the shoulder 33 of the cover (see Fig. 4).

As shown said tension means comprises a pair 7 of coiled tension springs 31 disposed at the sides of the latch with their ends hooked over pins 38, 39, one secured in the latch below the pin 28 and one secured above the pin 28 in a lug 40 formed onthe front edge of the cover. In either operative position of the latch the springs are disposed to one or the other side of a dead center line running through the axes of the pins 38, 28, 39. In swinging the latch from one of its operative positions to the other the pin 38 passes the dead center and the spring then acts to draw the latch in the direction of its movement with the latch completely engaged with the latch roller or its shoulder 32 in abutting engagement with the lug 40. r

Associated with'the cover is a clamping screw assembly 4 I ,the details of which arebest seen in Fig.6. As shown, the clamping screw assembly comprises among "other things a bored clamp screw 42' threadedly. mounted in a threaded hole in" the cover and adjustable therein toward and away from the piece of work. A lockinut 43,

threaded upon the clamp screw, is provided or locking the latter in adjustedgposition. 'When the lock nut is backed off somewhat the clamp The latch is further pro- 7 4 tight against the cover. The upper end of the clamp screw may be knurled to provide a grip to facilitate turning the screw or its upper end may be otherwise shaped to facilitate adjusting it. Within the bore of the clamp screw is the head 45 of a pin :25 which protrudes through a reduced opening at the lower end of the clamp screw. The upper portion of the bore is internally threaded, and a threaded plug. 65 is threadedly engaged with the internal threads ofv the clamp screw. Resilient means such as coiled compression spring ll is confined under compression between the plug and pin and serves to yieldingly thrust the pin outward ,irom the clamp screw. The pin can be held under more or less pressure by properly manipulating theplug M.

In practice the plug is screwed down to compress the spring and place it under the desired compression, and the clamp screw is screwed down 7 towards the piece of work, indicatedat W, until the pin has been moved inward inthe bore somewhat against the action of the spring so as to insure efiicient clampingflaction of the pin on the piece of work.

If desireda bushing carrying plate 56 may be bolted to a side of the base if holes are tobe drilled in a side of the piece ofwork; As is well understood the plate 5 0 is formed with" holes tion on the base relative to the bushings. As is well understood by those skilled in the art to which this invention pertains, the jig with the piece of work clamped therein is moved under. a

drill, bringing a bushing into alignment therewith and the drill is then lowered through the bushing, drilling the hole in the piece of work.

The modified form of the invention illustrated in Figs. 5 to 8 inclusive, inthemain, is substantially of the same construction as thatof the form illustrated in Figs. .1 to 4 inclusive, except that the overall height of the jig is slightly less and its general appearance is slightly'difierent The same reference characters are applied to the parts of the jig seenin Figs. 5 to 8 which correspend with the same parts of the jig seen in Figs. 1 to 4. I

In the form of quick latch shown in the modified form, the shoulder 32a is provided by a lug 32b formed upon the latch 21, which shoulder is arranged to abut against the top face of the cover whenever the latch is swung to the limit ofits upward swing relative the cover, as seen in Fig. 8. The points of connection between the tension springs 37a and the cover lug iila andthe-latch 21 are reversed with respect to-the corresponding points of connection of" the other form. In this case the pin 39a is located below the pin 28' and the pin 58a is located above said pin 28. However 7 the tension springs function precisely in the same manner as do the tension springs of the other form of the invention.

Having thus described my invention, it A obvious that various immaterial and obvious modifications of details maybe made inlthe same by one skilled in the art without departing from the spirit of my invention; henceI donot wish to'be understood as limiting myself to the exact.

form, construction, arrangement and 'combina- V tion of parts herein shown and described, or uses latch members being pivoted onthe cover and having a hand grip extending parallel with the axis'of the latch pivotfsaid pivoted latch member h aving also thumb and finger pieces extending laterally from the pivoted latch member, whereby the pivoted latch member is manipu-= lated to latch the cover to the base and to unlatch it therefrom.

,ZQA quick latchjig comprising a base arranged "to support the work and formed at one end with cover supporting uprights, a swingable cover pivotally mounted on said uprights and provided with spring urged work clamping means, a swingable latch pivotally carried by the cover at its free end, a cooperating latch member on the base adapted to be latchingly engaged by said latch, coactin shoulders on the cover and latch for limiting the movement of the latch relative to the cover when moved from its latching position, whereby said latch and cover may be raised and lowered as a unit, and a coiled spring attached at one end to the swingable latch and at the other end to the cover and arranged to yieldably hold the swingable latch in its latched position and to hold said latch with its shoulder in engagement with the shoulder on the cover.

3. In a quick 1atch jig, a base arranged to support a piece of work, a cover hinged to said base and provided with work clamping means, a latch member carried by the base, a latch pivotally mounted on the cover and having a hook memher for engaging said latch member and having also a hand grip whereby the latch is manipulated and a shoulder arranged to engage the cover to limit the upward swing of the latch on its pivot, said hook member having an arcuate face for engaging the latch member, which face is non-concentric with respect to the pivotal point of the latch, and a coiled spring attached at one end to the swingable latch and at the other end to the cover and arranged to yieldably hold the swingable latch in latched position and to hold said latch with its shoulder in engagement with the shoulder on the cover.

4. A quick latch for jigs comprising a latch member mounted on one element of a jig, a latch pivotally mounted on the other element of the jig and comprisin a hand grip and a hook memher, the latter having a face for engaging the latch member which face is non-concentric with respect to the pivot of the latch, the second named element of the jig and the latch having coacting shoulders cooperating to limit the upward swing of the latch, and both elements of the jig having coacting lugs to position the cover in its down position, resilient tension means carried by said second named ji element and by the latch, the point of connection between said resilient means and latch capable of being swung past a dead center line intersecting the pivot point of the latch and the point of connection between the resilient means and said second named jig element, whereby to hold the latch engaged with the latch member when the resilient means is disposed on one side of said dead center line, and

m hold-theshoulder of the latch in engagement with the coacting'shoulder ofthe cover when disposed on the other side of said dead center line.

'5. Ina jig having a base and a cover pivotally mounted thereon', a pair of vertical lugs-extending up from the base and -a pair "of vertical lugs extendin down from the cover and' capable of resting on the lugs of thebase, a latch roller disposed between the base'lugs and rotatively mounted thereon, a latch disposed between the cover lugs and pivotally mounted thereon, said latch including a hand grip, a shoulder and a hook member, the latter being arranged for latching engagement with the latch roller, and tension springs having points of connection with the cover and latch, and the point of connection of the springs with the latch bein arranged to be swung past the dead center line between its points of "connection and thepivot of the latch whereby to hold the latter in two operative positions, one in which the latch is engaged with the latch rollerand the other in which the shoulder of the latch is abutted against the cover.

6. In a quick latch jig, the combination of a base, a cover pivotally mounted thereon, latch means for latching the cover to the base, a hollow internally threaded clamp screw threadedly mounted in the cover, a spring pressed pin having an end protruding from said clamp screw and threaded means engaging the threads of the clamp screw for tensioning said spring.

7. In a quick latch jig, the combination of a base having a bifurcated base steadying leg projecting from one end thereof, ,a cover pivotally mounted on the other end of the base and provided with work clamping means, a latch roller rotatively mounted between the furcations of said leg, a latch pivotally mounted on the cover and having a hook member adapted to be swung between said furcations of the leg into latching engagement with the latch roller and tension means connectin said cover with the latch and adapted to hold the latter in latching engagement with the latch roller.

8. In a quick latch jig the combination of a base and a cover pivotally mounted thereon, a latch roller journaled at the front of said base, and a latch pivoted on the cover and having a hook member formed with a cam face adapted to be swung into latching engagement with said latch roller, said latch having a hand grip and a thumb piece and finger piece extending laterally from the body of the latch, substantially as and for the purpose set forth.

9. In a jig, the combination of a jig frame having one member for supporting a piece of work, a hollow internally threaded clamp screw threadedly mounted in another member of the frame and adjustable toward and away from the work, said clamp screw having an inturned annular flange at one end, a pin having an end protruding from said flanged end of the clamp screw, and a shoulder adapted to rest upon said flange, a coiled compression spring within the hollow of the clamp screw and bearing upon said pin, and a threaded plug engaging the internal threads of the clamp screw and bearing against the other end of the spring whereby to pre-tension said spring.

10. In a jig, the combination of a base adapted "to support a piece of work, a cover pivotally mounted on the base, latch means for latching the cover to the base, a hollow internally threaded clamp screw threadedly mounted in the cover and adjustable toward and away from the work,

a lock nut for locking the'clamp' screw to the cover, said clamp screw having an inwardly directed'annular flange at one end, a pin having an end protruding from the flangedend of said clamp screw, and a shoulder adapted to rest upon the 'fiange of the clamp screw, a threaded plug .threadedly mounted in said clamp screw, and a coiled compression spring in the hollow of said clamp screw and interposed between said pin and plug. I v r -11 In a quick latch jig, the combination of a base adapted to support a piece of work, a cover .pivotally mounted on said base,latch means for flange thereof, a plug threadedly mounted in the hollow of said clamp screw, and a coiled compression sprin interposed between said pin and plug.

- v y 7 ALBERT J. MATTER. REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number .Name 7 Date 837,811 Ebbeson Dec. 4, 1906 r 83,869 Fortin Apr. 7, 1908 1,044,071 Mulvihill a Nov. 12, 1912 1,472,630 Bourque Oct. 30, 1923 1,583, 46 Walters May 11, 1926 OTHER REFERENCES American Machinist, Dec. 16. 1926, pp. 989 991. American Machinist, Feb. 23, 1928, pp. 345-346. Pub. by McGraw-Hill Pub. C0,, 330 W. 42nd St.,

New York, N. Y. 

